Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the agent knows this is a write that overwrites the current value. The description adds that it 'replaces the current value,' which reinforces the destructive trait, but it doesn't mention permissions, validation requirements, error behavior, or consequences for related records.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single short sentence with the destructive replacement behavior front-loaded. It is efficient, though it could be slightly more informative without becoming bloated.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has full schema coverage, an output schema, and annotations covering safety/idempotency, the description is minimally adequate. However, for a destructive mutation on a linked bank account, the absence of any usage context or prerequisite warnings leaves a noticeable gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all four parameters are already documented in the schema, including the ledger credential restriction, currency example, and the accountId/account_id alias relationship. The description adds no parameter-level detail beyond the schema, which is the expected baseline when coverage is high.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource: setting a linked bank account's currency. It's distinguishable from siblings like mapBankAccount, listBankConnections, or refreshBankConnection which deal with different bank-connection operations. However, it doesn't explicitly say which sibling to use for adjacent tasks (mapping vs. setting currency), leaving some ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives no guidance on when to use this tool versus alternatives like mapBankAccount or refreshBankConnection, nor any prerequisites such as requiring an existing linked account. Only implied usage comes from the verb 'set'.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.